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Re: Simple Value Range Propagation
- From: Josef Zlomek <zlomj9am at artax dot karlin dot mff dot cuni dot cz>
- To: Steven Bosscher <s dot bosscher at student dot tudelft dot nl>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 9 Jun 2003 06:53:44 +0200
- Subject: Re: Simple Value Range Propagation
- References: <3EE3AF01.3070701@student.tudelft.nl>
> Also, if I read your patch correctly, you enable vrp at -O1.
> How about moving it to -O2, or maybe even -O3,
Of course, moving it to -O2 or -O3 is trivial. I thought that when
cleanup_cfg and if_convert is run at -O1 VRP might be run there as well.
> given the 2% compile time performance degradation vs. only 0.5%
> runtime performance improvement you reported?
I think 2% of compile time is relativelly cheap optimization pass,
and 0.5% is really good (it's more than I expected, it is also good in
comparision with other optimizations).
Josef